After some extensive testing, I could not find any reason why the material function LocalPosition node was failing to compile and defaulting to the world grid material when Packaging for HTML5.
I asked the user on the original post to try a range of different engine versions and platforms when building for HTML5 and all produced the same result.
I have attached the logs, the project, and a screenshot of the compile error. I was unsure if this was really expected or not, so I decided to enter a bug to get the final verdict.
1. Download and Open the attached project.
2. Package for HTML5
3. Search Logs for shader compiler warning.
Outcome: Material Function Local Position fails to compile and defaults to World grid material.
Expected: Material compiles successfully without any warnings.
Head over to the existingAnswerHub thread and let us know what's up.